There has been a statistically significant increase in the number of people killed or seriously injured in road traffic accidents between the years ending September 2015 and 2016. This indicates that there are a number of factors that have combined together to worsen some aspects of safety on Britain’s roads. However, there is some uncertainty in this owing to methodological changes. Although the number of people killed in road traffic accidents has increased between years, this change is small enough that it can be explained by the natural variation in deaths over time. Therefore there is not yet enough evidence to say that the number of fatalities is changing between years.